The present invention relates generally to a fluid cooled casting apparatus for the continuous casting of metallic strand and, more particularly, to such an apparatus having an improved cooling fluid seal which facilitates repair and maintenance.
It is well known in the prior art that it is possible to continuously cast a metallic strand from a molten mass of the metal by immersing the end of a refractory material die into the melt and then withdrawing the melt upwardly through the die and gradually cooling the melt into a solid strand. Generally, the cooling is accomplished by surrounding the die with a snuggly fitting coolerbody made of a material having good thermal conductivity characteristics, and circulating a cooling fluid, such as water, through the coolerbody to extract the heat of solidification therefrom. It is imperative that this cooling fluid be sealed completely within the coolerbody. Contact of the fluid with the strand within the die will contaminate the finished product; and, contact with the high-temperature melt may produce an explosion.
In U.S. Pat. No. 4,211,270, which has a common assignee as the present application, there is disclosed a coolerbody structure which employs a copper-gold braze to effect the fluid-containing seal. Not only is such a braze an increasingly more expensive procedure, but the more or less permanent nature of a braze interferes with maintenance or replacement of parts within the casting apparatus. The removal of the braze to allow separation of mating pieces of the coolerbody is a time-consuming procedure, and the heat and mechanical stresses thus induced often irretrievably damage elements of the coolerbody and prevents their reuse. Such waste means unnecessary expense.
The high temperatures experienced by the coolerbody during a typical casting operation have hindered the effectiveness of conventional O-ring seals. The prolonged exposure of the O-ring's constituent rubber material to these temperatures produces deterioration of the material and eventually destroys the effectiveness of the seal. Because of the potential safety hazard, such a seal has not heretofore been acceptable.
Therefore, it is an object of the present invention to provide a means for sealing and containing the cooling fluid within the interior of a coolerbody and to do so in a manner that facilitates disassembly of the coolerbody for repair.
It is a further object of the present invention to provide a sealing means whose removal during disassembly does not irreversibly damage adjacent components of the casting apparatus.
It is still a further object of the present invention to provide a simple, reliable sealing means which can withstand the typically high temperatures associated with metal casting procedures.